Mirena Overview

What are Mirena IUD’s side effects?

Like most drugs, Mirena, a form of birth control, may cause mild to serious side effects. The lists below contain some of the more common side effects this intrauterine device (IUD) may cause. But they don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

• your age
• other health conditions you have
• other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of Mirena. They can also suggest ways to help reduce or relieve them.

Mild side effects

Below is a list of some of the mild side effects Mirena can cause. To learn about others, talk with your doctor or pharmacist, or read Mirena’s prescribing information.

Mild side effects of Mirena that have been reported include:

• changes in menstrual bleeding patterns, such as spotting
• pain or cramps in your pelvis and abdomen
• amenorrhea (not having periods)
• headache
• migraine headache
• vaginal discharge
• swelling or irritation of the vagina and vulva (external vaginal area)
• mild allergic reaction*

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Allergic reaction” section below.

Serious side effects

Serious side effects from Mirena can occur, but they aren’t common. If you have serious side effects from Mirena, call your doctor right away. But if you think you’re having a medical emergency, you should immediately call 911 or your local emergency number.

Serious side effects of Mirena that have been reported include:

• depression
• pelvic infection, such as pelvic inflammatory disease (PID)
• ovarian cysts
• risk of internal injury, such as perforation (puncture) of the uterus
• sepsis (a serious condition caused by your body’s reaction to an infection)
• IUD expulsion (falling out of the uterus), which may cause loss of effectiveness
• risk of serious pregnancy complications if pregnancy occurs while using Mirena*
• severe allergic reaction†

* To learn more about this risk, see the “Pregnancy and breastfeeding” section in “What should be considered before using Mirena?” below.
† To learn more about this side effect, see the “Allergic reaction” section below.

Allergic reaction

Some people may have an allergic reaction to Mirena. While allergic reactions weren’t seen in studies of Mirena, some people have reported them after it came on the market.

Symptoms of a mild allergic reaction can include:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, usually in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.

Call your doctor right away if you have an allergic reaction to Mirena. But if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

What are some frequently asked questions about Mirena?

Below are answers to some common questions about Mirena.

Is Mirena similar to Liletta and Kyleena?

Yes, they are all intrauterine devices (IUDs) used to help prevent pregnancy. Mirena, Liletta, Kyleena, and Skyla IUDs all contain the same active ingredient: levonorgestrel. They are hormonal forms of birth control.

A copper IUD called Paragard is also available. It does not contain any hormone ingredients.

All these IUDs are used to help prevent pregnancy. Mirena is also approved to treat heavy periods.

Different kinds of IUDs vary regarding how long they’re used to help prevent pregnancy. The range is from 3 to 10 years. The Mirena IUD is designed to stay in the uterus for up to 8 years to help prevent pregnancy.

Talk with your doctor to discuss which option may be right for you.

How does Mirena work?

Mirena is an IUD, a T-shaped piece of plastic that’s placed in the uterus. It contains the active ingredient levonorgestrel. (An active ingredient is what makes a drug or device work.) Mirena releases levonorgestrel into your uterus over time.

Mirena is used to help prevent pregnancy. It’s not known exactly how Mirena works to do this. The drug is thought to thicken cervical mucus and block sperm movement. This makes it more difficult for sperm to enter the uterus.

Mirena is also used to treat heavy periods. For this use, the drug is thought to work by making the endometrium (the lining of the uterus) thinner.

Will I experience side effects when Mirena is removed or inserted?

It’s possible. Some people have pain, bleeding, or dizziness when Mirena is removed or inserted. (It’s inserted and removed by a healthcare professional at a doctor’s office.)

People with a history of epilepsy may be at risk of having a seizure when Mirena is removed or inserted. And people who are prone to fainting or feeling faint may be at risk of this side effect when having Mirena inserted or removed.

It’s not known how common or rare these side effects are. Talk with your doctor if you’re having bothersome side effects, such as pain, after Mirena removal or insertion. They may recommend a pain reliever for you to take.

Can Mirena be used for endometriosis?

Mirena isn’t specifically approved to treat endometriosis. It’s a form of birth control used to help prevent pregnancy and manage heavy periods.

With endometriosis, tissue that’s similar to the endometrium (the lining of the uterus) grows in other areas inside your body.

Doctors often prescribe birth control off-label* to help manage certain symptoms of endometriosis. For example, heavy periods are a common symptom of this condition. So doctors may prescribe Mirena for people with heavy periods who prefer to use an IUD as a birth control method.

If you have questions about treatment options for endometriosis, talk with your doctor.

* With off-label use, a drug is prescribed for a condition it isn’t approved to treat.

Does Mirena cause you to not have a period?

It’s possible. In studies, about 2 out of every 10 people stopped having periods after using Mirena for 1 year. In rare cases, missing periods during Mirena treatment may be a sign of pregnancy. (Mirena is used to help prevent pregnancy.)

If you think you may be pregnant while using Mirena, take a pregnancy test and call your doctor right away. If you’re pregnant, your doctor will likely suggest you have Mirena removed. (To learn more about this, see the “Pregnancy and breastfeeding” section under “What should be considered before using Mirena?” below.)

What is Mirena used for?

Mirena is a kind of birth control in the form of an intrauterine device (IUD). It’s used to:

• prevent pregnancy in females* of reproductive age (those able to become pregnant)
• treat heavy periods in females who choose to use an IUD as a birth control method

Specifically, Mirena belongs to a group of drugs called progestins. These are synthetic versions of progesterone, a kind of hormone.

In studies, the Mirena IUD was shown to be effective in preventing pregnancy for up to 8 years. If you decide to stop using Mirena, you can have your doctor remove the IUD at any time. To continue using this IUD as your birth control method, it will need to be removed and replaced every 8 years.

It’s not known exactly how Mirena works to prevent pregnancy. The drug is thought to thicken cervical mucus and block sperm movement. This makes it more difficult for sperm to enter the uterus.

Mirena is also used to help manage heavy periods. For this use, the drug is thought to work by making the endometrium (the lining of the uterus) thinner.

To treat heavy periods, the Mirena IUD stays in the uterus for up to 5 years. After 5 years, you and your doctor will decide whether you’ll continue this treatment. If so, they’ll remove the Mirena IUD and insert a new one.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

What should be considered before using Mirena?

Before having a Mirena IUD inserted, it’s important to talk with your doctor. Tell them about any medical conditions you have, your overall health, and any drugs and supplements you take. These and other factors are described in more detail below.

Interactions

Using a medication with certain vaccines, foods, and other things can affect how the medication works. These effects are called interactions.

Before having a Mirena intrauterine device (IUD) inserted, be sure to tell your doctor about all medications you take, including prescription and over-the-counter kinds. Also, describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with Mirena.

For information about drug-condition interactions, see the “Warnings” section below.

Interactions with drugs or supplements

There currently aren’t any medications or supplements known to interact with Mirena. But this doesn’t mean interactions with Mirena will not be recognized in the future. For example, new drugs may be approved that interact with Mirena.

For this reason, you should tell your doctor and pharmacist about any medications you take. This way, they can check for any new interactions during your treatment.

Other interactions

No foods or vaccines are known to interact with Mirena.

Warnings

Mirena can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Talk with your doctor about your health history before having a Mirena IUD inserted.

If you have certain conditions or factors, your doctor will likely not prescribe Mirena due to the risk of harm. These conditions and factors, which are listed below, may increase the risk of Mirena’s serious side effects:

• being pregnant or possibly pregnant (Mirena is not to be used as emergency birth control.)
• having an irregularly shaped uterus
• having past or current pelvic inflammatory disease (PID) or an increased risk of it
• cancer of the uterus, cervix, breast, or other cancer that’s sensitive to hormones
• inflammation of the endometrium (lining of the uterus) or infection related to an abortion or a pregnancy loss in the past 3 months
• bleeding of the uterus with no known cause
• active vaginal infection
• disease or tumor of the liver
• a previously inserted IUD that hasn’t been removed
• an allergic reaction to Mirena or any of its ingredients

Other factors may also affect whether Mirena is a good treatment option for you.

History of ectopic pregnancy, tubal surgery, or pelvic infection. Mirena is used to prevent pregnancy and is highly effective for this purpose. But if pregnancy occurs while using a Mirena IUD, there can be serious complications.

The most common complication is ectopic pregnancy (when a fertilized egg attaches somewhere outside of the uterus, such as on a fallopian tube). If you’ve had an ectopic pregnancy, tubal surgery, or pelvic infection in the past, talk with your doctor. They may monitor you more closely during treatment.

Migraine. Mirena may cause headache or migraine headache as a side effect. If you already have migraine episodes, using this IUD may make your symptoms more frequent or more severe. Talk with your doctor to determine whether Mirena is right for you.

History of blood clots, stroke, or heart attack. In rare cases, using Mirena may lead to blood clots, stroke, or heart attack. These side effects weren’t seen in studies of Mirena but have been reported since it came on the market. Before using Mirena, tell your doctor if you’ve had blood clots, stroke, or heart attack in the past. They can determine whether Mirena is a safe option for you.

Mirena and alcohol

Alcohol should not interact with Mirena. Talk with your doctor if you have questions about consuming alcohol during Mirena treatment.

Pregnancy and breastfeeding

Mirena should not be used during pregnancy. Mirena is used to prevent pregnancy and is highly effective for this purpose.

That said, if pregnancy occurs while using a Mirena IUD, there can be serious complications. The most common complication is ectopic pregnancy (when a fertilized egg attaches somewhere outside of the uterus, such as on a fallopian tube). This could lead to the loss of fertility (the ability to become pregnant).

If you think you’re pregnant while using Mirena, take a pregnancy test and call your doctor right away. If you are pregnant, they’ll likely suggest removal of the Mirena IUD.

Removing Mirena may result in pregnancy loss. But leaving it in place during pregnancy may also cause pregnancy loss. Other complications of leaving the IUD in place during pregnancy have been reported and include:

• premature (early) labor or delivery
• problems with fetal development (commonly known as birth defects)
• pregnancy loss
• septic shock
• death (in rare cases)

Leaving an IUD in place during pregnancy has also caused death, in rare cases.

Talk with your doctor if you have questions about the risks of becoming pregnant during Mirena treatment.

While it’s not known for sure, Mirena is generally considered safe to use while breastfeeding. However, breastfeeding while using Mirena may increase the risk of perforation (puncture) of the uterus. This is a rare but serious side effect of the Mirena IUD.

Levonorgestrel (the active ingredient* in Mirena) passes into breast milk, so a breastfed child may be exposed to it. But no side effects have been reported in breastfed children whose mothers used this IUD.

In some cases, decreased breast milk production has been reported with Mirena.

Talk with your doctor if you have questions about Mirena and breastfeeding.

* An active ingredient is what makes a drug work.

What does Mirena cost?

Costs of prescription drugs can vary depending on several factors. These include whether you have insurance and if so, what your plan covers and whether you have a copay for seeing your doctor. (Keep in mind that Mirena is inserted and removed by a healthcare professional at a doctor’s office.)

If you have questions about how to pay for medications, talk with your doctor or pharmacist. A copay savings program may also be available for Mirena. And you can check out this article to learn more about saving money on prescription drugs.

What is Mirena’s dosage?

Mirena’s dosage over time varies depending on whether you’re using it to prevent pregnancy or help manage heavy periods.

Form and strength

Mirena is an intrauterine device (IUD). It’s a T-shaped piece of plastic that’s placed in the uterus. It’s inserted by a healthcare professional in a doctor’s office.

Mirena contains a total of 52 milligrams (mg) of levonorgestrel (its active ingredient*). It releases small amounts of this drug into your uterus over time.

* An active ingredient is what makes a drug work.

Recommended dosages

Mirena is used to help prevent pregnancy. It’s also used to treat heavy periods.

Dosage for helping to prevent pregnancy

To help prevent pregnancy, a healthcare professional will insert the Mirena IUD into your uterus. For this use, Mirena is meant to stay in place for up to 8 years.

Dosage for heavy periods

To treat heavy periods, a healthcare professional will insert the Mirena IUD into your uterus. For this use, Mirena is meant to stay in place for up to 5 years.

Questions about Mirena’s dosing

Below are some common questions about Mirena’s dosing.

• Will I need to use Mirena long term? Mirena is meant to be a long-term treatment. Talk with your doctor to determine how long you’ll use it.
• How long does Mirena take to work to prevent pregnancy? It depends on when Mirena is inserted in relation to your period. If Mirena is inserted within 7 days after the start of your period, it starts working right away. If Mirena is inserted at any other point, the drug may take longer to start working. In this case, you should use a backup birth control method, such as condoms, for 1 week.

How is Mirena inserted and removed?

Your doctor will explain how Mirena will be inserted, how long it will stay in place, and reasons it may need to be removed. They’ll also talk with you about side effects you may have and how often you need to have Mirena replaced.

How Mirena is inserted

Mirena is inserted into the uterus by a healthcare professional in a doctor’s office. The process only takes a few minutes. After insertion, you’ll have an appointment with your doctor 4 to 6 weeks later. They’ll check to ensure Mirena was placed properly and will likely recheck it each year when you have your annual exam.

When to have Mirena inserted

Your doctor will explain when you should have Mirena inserted. The timing depends on several factors such as:

• whether you’re switching to Mirena after using a different method of birth control
• what your previous birth control method was
• whether you’ve recently given birth or had a pregnancy loss or an abortion

Using Mirena with other drugs

Mirena is a kind of birth control. Keep in mind that it does not protect against sexually transmitted infections (STIs). If STIs are a concern, you may want to use another birth control method, such as condoms, for this purpose.